Fast and accurate mock catalogue generation for low-mass galaxies

We present an accurate and fast framework for generating mock catalogues including lowmass haloes, based on an implementation of the COmoving Lagrangian Acceleration (COLA) technique. Multiple realisations of mock catalogues are crucial for analyses of large-scale structure, but conventional N-body simulations are too computationally expensive for the production of thousands of realizations. We show that COLA simulations can produce accurate mock catalogues with a moderate computation resource for low-to intermediate-mass galaxies in 10 12 M haloes, both in real and redshift space. COLA simulations have accurate peculiar velocities, without systematic errors in the velocity power spectra for k 0. 15 h Mpc -1, and with only 3-per cent error for k 0. 2 h Mpc -1. We use COLA with 10 time steps and a Halo Occupation Distribution to produce 600 mock galaxy catalogues of the WiggleZ Dark Energy Survey. Our parallelized code for efficient generation of accurate halo catalogues is publicly available at github. com/junkoda/colaₕalo.